Dietary vitamin A requirement of juvenile Wuchang bream (Megalobrama amblycephala) determined by growth and disease resistance

In a word, an excess or deficiency of VA reduced WBC, RBC, HBG, C3 and C4 contents, increased blood AST and ALT activities and enhanced morality after A. hydrophila infection. Taken together, our results suggest that the optimum requirement of dietary VA for juvenile Wuchang bream is 3914 IU kg− 1 of diet based on the broken-line regression analysis of FCR versus different dietary VA levels, respectively.